1. Field of the Invention
This invention relates generally to bicycle transmission shift control, and more particularly, to a bicycle handlebar mounted system incorporating a continuous cable, a twin cable or a single cable arrangement connected to a bicycle transmission derailleur so that pulling on one portion of the continuous cable, pulling on one of the twin cables or pulling on the end of the single cable at the handlebar moves the derailleur to move a drive chain from one set of gears to another. Alternatively, by pulling in a different direction on the continuous cable, pulling on the other of the twin cables or releasing tension in the single cable at the handlebar moves the derailleur to move the drive chain in the opposite direction from one set of gears to another. The bicycle handlebar mounted system of the invention also can include a mounting for a cycling computer.
2. Description of the Related Art
Many types of bicycle transmission shift devices using derailleurs have been used. Predominantly, these devices interconnect a derailleur with a shifting device using a cable and spring system. The cable can be pulled by the shifting device in one direction to move the derailleur. Alternatively, the shifting device can be operated to release tension from the cable and then the spring system acting on the cable moves the derailleur in the opposite direction.
Shifting devices that have been used include at least lever type devices and twist-grip type devices. These shifting devices have been mounted at various locations on bicycles such as frames and handlebars. These devices have been located at various positions on bicycles where a rider is supposed to easily find and operate them. As far as operation is concerned, it is desired that the shifters function easily with position feedback and do not require much force to operate.
Lever type transmission shifting devices have been mounted on bike frames or on handlebars—e.g., at the ends of handlebars and in association with brake levers. These locations for mounting lever type transmission shifting devices have not always been considered most convenient. In particular, locating these devices on bicycle frames has not always been favored because there are riders who have found them difficult to locate and operate when standing and pedaling—such as when biking up hills. Riders have also found that even mounting lever type transmission shifting devices at the ends of handlebars may not be as convenient as they require.
With respect to handlebar twist grip type transmission shifting devices, it has been found that these type systems often are heavy and therefore add bulk to handlebars. These weight and bulk consequences result from extensive gear and other mechanical arrangements required to implement such systems. The extent and complexities of such arrangements unavoidably result in lowered reliability for the grip type transmission shifting devices. Further frustrating utility of these twist grip type systems is the fact that their complexity also adversely impacts making repairs, which can be a significant issue if repairs must be made on the road.
A further alternative system involves combining a brake lever with a separate smaller lever that are mounted together so that both the brake lever and the smaller lever in combination can be deflected toward the center of the bike to move a derailleur to move the bicycle chain. The combined brake lever and smaller lever also are arranged and mounted so they can be moved back to their original positions, this return movement of the levers permits the brake lever to be deflected in order operate a brake. To have a derailleur move the bike chain in an opposite direction, the smaller lever is mounted so that it can be deflected toward the center of the bike without deflection of the brake lever. When the smaller lever is so deflected without deflection of the brake lever a mechanical system—such as a ratchet and pinion system—is operated to relieve tension on a connected derailleur cable that is spring loaded at the derailleur mounting to move the derailleur in an opposition direction. All of these combinations of mechanical arrangements, including multiple levers and functions for the levers and associated movements and operations again introduce weight and complexities.